Retweetie is a SIMBL plugin for Mac that makes Tweetie use Twitter's native retweeting functionality. No longer do you get a "RT @user: " tweet, but instead a real retweet. Just Repost your tweet as usual and let ReTweetie handle the rest.

London, England (CNN) -- Facebook this week announced a new way to express your interests -- a "Like" button that's set to appear all around the web. Click the button, and the Web page is shared with your friends.
What's more, every "Like" you submit ensures Facebook (and its partner sites) can deliver a more personalized experience to you.
It's a simple yet powerful feature -- one that delivers a significant blow to rival Twitter. Once the network effects take hold, it's frankly hard to imagine how any company could unseat Facebook's social networking dominance in the months to come. Without a counterattack, even Google may one day be dethroned.

Manage Social Networks Through Your Email

NutshellMail brings a summary of your social network updates to your inbox in a single email on your schedule.

Twitter success is based on the simplicity of the service. However, the website, as well as various standalone Twitter clients are becoming more and more cluttered with useless features and other junk. Therefore, I stripped it to the basics and now it's the first twitter client I am happy with.